There is no need to stop big miners, his gains are in full proportion to his efforts.
There are still many essential differences between mining pools and large miners.
For example, in traditional POW, there are 10 nodes in the entire network, the 5 are solo, and the other 5 are alliances, then the chance of the alliance winner is not 5/10, but 27/32, which is much greater than 5/10 , this is the key to unfairness.
In our network, your chance of winning is always equal to the proportion of your contribution to the entire network.
In addition, since there is no profit advantage in cooperation, there will be no mining pools. In the end, there will be more large miners without alliance and some free small miners, and the system will be more decentralized, and thus more safety
I see your point of view: the nodes.
Here is mine: the coins.
Maybe you fixed the node problem pools have, but you have a new problem - all the coins goes now to a single owner, instead of multiple owners. This is why I've said is worst than traditional PoW, instead of a pool getting 50% of mined coins (which will be spread among all individual miners) now we have 1 miner getting 50% of the coins, but we are pool free.
And not to be negligible, with this approach the scenario can go like this: Let's say I mine solo (because there are no pools involved) but since is not profitable for me because 1 single miner gets 50% of all block, I leave. So will do all the small miners, if is not profitable anymore and this will lead him to mine more and more blocks until probably he will mine 100% of the blocks.
Now tell me, where is the decentralization?